using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        var str = "AabbCCDDEEgghh";

        var LV = LCount(str);

        foreach(var km in LV)

        {

            Console.WriteLine($"{km.Key}:{km.Value}");

        }

    }

    //Count the occurence of words

​

    public static Dictionary<char, int> LCount(string word)

    {

        return  word.GroupBy(x => char.ToLower(x)).ToDictionary(b => b.Key, b => b.Count());

    }

}